Blends of microcrystalline chitosan (MCCh) with cellulose xhanthate alkaline solutions were prepared to investigate the effects of aqueous MCCh gel concentration and additives on the spinnability of hybrid cellulose/chitosan fibers and their properties. The properties of the spinning solution were mainly dependent on the concentration of MCCh in the aqueous gel-like dispersion and the amount mixed into the cellulose xhanthate solution. Sodium alginate chemically close to cellulose and chitosan was used as an additive to improve the miscibility of chitosan due to the ionic bonds formed with chitosan 2-amino groups. Using an optimized ratio of 2 : 1 of MCCh to the sodium alginate, a maximum of 6% of MCCh calculated from alpha-cellulose content could be introduced into the sodium xhanthate solution containing originally 9% of alpha-cellulose. The yield of MCCh in the resulting fibers was dependent on the molecular mass, and varied between 73- 82%. The strength, elongation, and color of the resulting hybrid fibers were only slightly changed and the WRV remarkably increased compared to standard fibers. (C) 2000 John Wiley & Sons, Inc.